Support a primary entry point for bundles.

src/functionalTest/groovy/com/autonomousapps/jvm/BundleSpec.groovy

@@ -0,0 +1,24 @@
+package com.autonomousapps.jvm
+
+import com.autonomousapps.jvm.projects.BundleProject
+
+import static com.autonomousapps.utils.Runner.build
+import static com.google.common.truth.Truth.assertThat
+
+final class BundleSpec extends AbstractJvmSpec {
+
+  def "can define entry point to bundle (#gradleVersion)"() {
+    given:
+    def project = new BundleProject()
+    gradleProject = project.gradleProject
+
+    when:
+    build(gradleVersion, gradleProject.rootDir, 'buildHealth')
+
+    then:
+    assertThat(project.actualProjectAdvice()).containsExactlyElementsIn(project.expectedProjectAdvice)
+
+    where:
+    gradleVersion << gradleVersions()
+  }
+}

src/functionalTest/groovy/com/autonomousapps/jvm/projects/BundleProject.groovy

@@ -0,0 +1,155 @@
+package com.autonomousapps.jvm.projects
+
+import com.autonomousapps.AbstractProject
+import com.autonomousapps.kit.GradleProject
+import com.autonomousapps.kit.Plugin
+import com.autonomousapps.kit.Source
+import com.autonomousapps.kit.SourceType
+import com.autonomousapps.model.Advice
+import com.autonomousapps.model.ProjectAdvice
+
+import static com.autonomousapps.AdviceHelper.*
+import static com.autonomousapps.kit.Dependency.project
+
+final class BundleProject extends AbstractProject {
+
+  final GradleProject gradleProject
+
+  BundleProject() {
+    this.gradleProject = build()
+  }
+
+  private GradleProject build() {
+    def builder = newGradleProjectBuilder()
+    builder.withRootProject {
+      it.withBuildScript { bs ->
+        bs.additions = """
+          dependencyAnalysis {
+            dependencies {
+              bundle('facade') {
+                primary(':entry-point')
+                includeDependency(':entry-point')
+                includeDependency(':used')
+              }
+            }
+          }
+        """.stripIndent()
+      }
+    }
+    // consumer -> unused -> entry-point -> used
+    // consumer only uses :used.
+    // :used and :entry-point are in a bundle
+    // plugin should advise to add :entry-point and remove :unused.
+    // it should _not_ advise to add :used.
+    builder.withSubproject('consumer') { c ->
+      c.sources = sourcesConsumer
+      c.withBuildScript { bs ->
+        bs.plugins = [Plugin.javaLibraryPlugin]
+        bs.dependencies = [
+          project('implementation', ':unused')
+        ]
+      }
+
+    }
+    builder.withSubproject('unused') { s ->
+      s.sources = sourcesUnused
+      s.withBuildScript { bs ->
+        bs.plugins = [Plugin.javaLibraryPlugin]
+        bs.dependencies = [
+          project('api', ':entry-point')
+        ]
+      }
+    }
+    builder.withSubproject('entry-point') { s ->
+      s.sources = sourcesEntryPoint
+      s.withBuildScript { bs ->
+        bs.plugins = [Plugin.javaLibraryPlugin]
+        bs.dependencies = [
+          project('api', ':used')
+        ]
+      }
+    }
+    builder.withSubproject('used') { s ->
+      s.sources = sourcesUsed
+      s.withBuildScript { bs ->
+        bs.plugins = [Plugin.javaLibraryPlugin]
+      }
+    }
+
+    def project = builder.build()
+    project.writer().write()
+    return project
+  }
+
+  private sourcesConsumer = [
+    new Source(
+      SourceType.JAVA, "Consumer", "com/example/consumer",
+      """\
+        package com.example.consumer;
+        
+        import com.example.used.Used;
+        
+        public class Consumer {
+          private Used used;
+        }
+      """.stripIndent()
+    )
+  ]
+
+  private sourcesUnused = [
+    new Source(
+      SourceType.JAVA, "Unused", "com/example/unused",
+      """\
+        package com.example.unused;
+        
+        import com.example.entry.EntryPoint;
+        
+        public abstract class Unused {
+          public abstract EntryPoint getEntryPoint();
+        }
+      """.stripIndent()
+    )
+  ]
+
+  private sourcesEntryPoint = [
+    new Source(
+      SourceType.JAVA, "EntryPoint", "com/example/entry",
+      """\
+        package com.example.entry;
+        
+        import com.example.used.Used;
+        
+        public abstract class EntryPoint {
+          public abstract Used getUsed();
+        }
+      """.stripIndent()
+    )
+  ]
+
+  private sourcesUsed = [
+    new Source(
+      SourceType.JAVA, "Used", "com/example/used",
+      """\
+        package com.example.used;
+        
+        public class Used {}
+      """.stripIndent()
+    )
+  ]
+
+  Set<ProjectAdvice> actualProjectAdvice() {
+    return actualProjectAdvice(gradleProject)
+  }
+
+  private final Set<Advice> consumerAdvice = [
+    Advice.ofAdd(projectCoordinates(':entry-point'), 'implementation'),
+    Advice.ofRemove(projectCoordinates(':unused'), 'implementation')
+  ]
+
+  final Set<ProjectAdvice> expectedProjectAdvice = [
+    projectAdviceForDependencies(':consumer', consumerAdvice),
+    emptyProjectAdviceFor(':unused'),
+    emptyProjectAdviceFor(':entry-point'),
+    emptyProjectAdviceFor(':used')
+  ]
+}

src/main/kotlin/com/autonomousapps/extension/DependenciesHandler.kt

@@ -3,11 +3,9 @@
 package com.autonomousapps.extension
 
 import com.autonomousapps.model.Coordinates
-import org.gradle.api.Action
-import org.gradle.api.GradleException
-import org.gradle.api.InvalidUserDataException
-import org.gradle.api.Named
+import org.gradle.api.*
 import org.gradle.api.model.ObjectFactory
+import org.gradle.api.provider.Property
 import org.gradle.api.provider.SetProperty
 import org.gradle.api.tasks.Input
 import org.gradle.kotlin.dsl.setProperty
@@ -62,30 +60,41 @@ open class DependenciesHandler @Inject constructor(objects: ObjectFactory) {
     }
   }
 
-  internal fun serializableBundles(): SerializableBundles {
-    return SerializableBundles.of(bundles.asMap.map { (name, groups) ->
-      name to groups.includes.get()
-    }.toMap())
-  }
+  internal fun serializableBundles(): SerializableBundles = SerializableBundles.of(bundles)
 
   class SerializableBundles(
-    @get:Input
-    val bundles: Map<String, Set<Regex>>
+    @get:Input val rules: Map<String, Set<Regex>>,
+    @get:Input val primaries: Map<String, String>
   ) : Serializable {
 
     /** Returns the collection of bundle rules that [coordinates] is a member of. (May be 0 or more.) */
-    fun matchingBundles(coordinates: Coordinates): Map<String, Set<Regex>> {
-      if (bundles.isEmpty()) return emptyMap()
+    internal fun matchingBundles(coordinates: Coordinates): Map<String, Set<Regex>> {
+      if (rules.isEmpty()) return emptyMap()
 
-      return bundles.filter { (_, regexes) ->
+      return rules.filter { (_, regexes) ->
         regexes.any { regex ->
           regex.matches(coordinates.identifier)
         }
       }
     }
 
     companion object {
-      internal fun of(map: Map<String, Set<Regex>>) = SerializableBundles(map)
+      internal fun of(
+        bundles: NamedDomainObjectContainer<BundleHandler>
+      ): SerializableBundles {
+        val rules = mutableMapOf<String, Set<Regex>>()
+        val primaries = mutableMapOf<String, String>()
+        bundles.asMap.map { (name, groups) ->
+          rules[name] = groups.includes.get()
+
+          val primary = groups.primary.get()
+          if (primary.isNotEmpty()) {
+            primaries[name] = primary
+          }
+        }
+
+        return SerializableBundles(rules, primaries)
+      }
     }
   }
 
@@ -97,6 +106,9 @@ open class DependenciesHandler @Inject constructor(objects: ObjectFactory) {
 /**
  * ```
  * bundle("kotlin-stdlib") {
+ *   // 0 (Optional): Specify the primary entry point that the user is "supposed" to declare.
+ *   primary("org.something:primary-entry-point")
+ *
  *   // 1: include all in group as a single logical dependency
  *   includeGroup("org.jetbrains.kotlin")
  *
@@ -116,8 +128,14 @@ open class BundleHandler @Inject constructor(
 
   override fun getName(): String = name
 
+  val primary: Property<String> = objects.property(String::class.java).convention("")
   val includes: SetProperty<Regex> = objects.setProperty<Regex>().convention(emptySet())
 
+  fun primary(identifier: String) {
+    primary.set(identifier)
+    primary.disallowChanges()
+  }
+
   fun includeGroup(group: String) {
     include("^$group:.*")
   }

src/main/kotlin/com/autonomousapps/internal/Bundles.kt

@@ -0,0 +1,120 @@
+package com.autonomousapps.internal
+
+import com.autonomousapps.extension.DependenciesHandler.SerializableBundles
+import com.autonomousapps.graph.Graphs.children
+import com.autonomousapps.graph.Graphs.reachableNodes
+import com.autonomousapps.model.Advice
+import com.autonomousapps.model.Coordinates
+import com.autonomousapps.model.DependencyGraphView
+import com.autonomousapps.model.ProjectCoordinates
+import com.autonomousapps.model.declaration.Bucket
+import com.autonomousapps.model.intermediates.Usage
+
+/**
+ * :proj
+ * |
+ * B -> unused, not declared, but top of graph (added by plugin)
+ * |
+ * C -> used as API, part of bundle with B. Should not be declared!
+ */
+internal class Bundles(private val dependencyUsages: Map<Coordinates, Set<Usage>>) {
+
+  // a sort of adjacency-list structure
+  private val parentKeyedBundle = mutableMapOf<Coordinates, MutableSet<Coordinates>>()
+
+  // link child/transitive node to parent node (which is directly adjacent to root project node)
+  private val parentPointers = mutableMapOf<Coordinates, Coordinates>()
+
+  // if a set of rules has a primary identifier, use this to map advice to it
+  private val primaryPointers = mutableMapOf<Coordinates, Coordinates>()
+
+  operator fun set(parentNode: Coordinates, childNode: Coordinates) {
+    // nb: parents point to themselves as well. This is what lets DoubleDeclarationsSpec pass.
+    parentKeyedBundle.merge(parentNode, mutableSetOf(parentNode, childNode)) { acc, inc ->
+      acc.apply { addAll(inc) }
+    }
+    parentPointers.putIfAbsent(parentNode, parentNode)
+    parentPointers.putIfAbsent(childNode, parentNode)
+  }
+
+  fun setPrimary(primary: Coordinates, subordinate: Coordinates) {
+    primaryPointers.putIfAbsent(subordinate, primary)
+  }
+
+  fun hasParentInBundle(coordinates: Coordinates): Boolean = parentPointers[coordinates] != null
+
+  fun primary(advice: Advice): Advice {
+    check(advice.isAdd()) { "Must be add-advice" }
+
+    return primaryPointers[advice.coordinates]?.let { primary ->
+      advice.copy(coordinates = primary)
+    } ?: advice
+  }
+
+  fun hasUsedChild(coordinates: Coordinates): Boolean {
+    val children = parentKeyedBundle[coordinates] ?: return false
+    return children.any { child ->
+      dependencyUsages[child].orEmpty().any { it.bucket != Bucket.NONE }
+    }
+  }
+
+  companion object {
+    fun of(
+      projectNode: ProjectCoordinates,
+      dependencyGraph: Map<String, DependencyGraphView>,
+      bundleRules: SerializableBundles,
+      dependencyUsages: Map<Coordinates, Set<Usage>>,
+      ignoreKtx: Boolean
+    ): Bundles {
+      val bundles = Bundles(dependencyUsages)
+
+      // Handle bundles with primary entry points
+      bundleRules.primaries.forEach { (name, primaryId) ->
+        val regexes = bundleRules.rules[name]!!
+        dependencyGraph.forEach { (_, view) ->
+          view.graph.reachableNodes(projectNode)
+            .find { it.identifier == primaryId }
+            ?.let { primaryNode ->
+              val reachableNodes = view.graph.reachableNodes(primaryNode)
+              reachableNodes.filter { subordinateNode ->
+                regexes.any { it.matches(subordinateNode.identifier) }
+              }.forEach { subordinateNode ->
+                bundles.setPrimary(primaryNode, subordinateNode)
+              }
+            }
+        }
+      }
+
+      // Handle bundles that don't have a primary entry point
+      dependencyGraph.forEach { (_, view) ->
+        view.graph.children(projectNode).forEach { parentNode ->
+          val rules = bundleRules.matchingBundles(parentNode)
+
+          // handle user-supplied bundles
+          if (rules.isNotEmpty()) {
+            val reachableNodes = view.graph.reachableNodes(parentNode)
+            rules.forEach { (_, regexes) ->
+              reachableNodes.filter { childNode ->
+                regexes.any { it.matches(childNode.identifier) }
+              }.forEach { childNode ->
+                bundles[parentNode] = childNode
+              }
+            }
+          }
+
+          // handle dynamic ktx bundles
+          if (ignoreKtx) {
+            if (parentNode.identifier.endsWith("-ktx")) {
+              val baseId = parentNode.identifier.substringBeforeLast("-ktx")
+              view.graph.children(parentNode).find { child ->
+                child.identifier == baseId
+              }?.let { bundles[parentNode] = it }
+            }
+          }
+        }
+      }
+
+      return bundles
+    }
+  }
+}